scholarly journals A Voltage Sag Severity Evaluation Method for the System Side which Considers the Influence of the Voltage Tolerance Curve and Sag Type

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5065
Author(s):  
Yonghai Xu ◽  
Xingguan Fan ◽  
Siying Deng ◽  
Chunhao Niu
Keyword(s):  
Evaluation Method ◽  
Evaluation Model ◽  
Reference Value ◽  
User Equipment ◽  
Voltage Sag ◽  
Energy Index ◽  
Weight Calculation ◽  
Interval Evaluation ◽  
Tolerance Curve ◽  
Interval Weight

Considering the influence of user equipment voltage tolerance characteristics and sag types on the evaluation results, this paper proposes a voltage sag severity evaluation method for the system side which considers the influence of the voltage tolerance curve and sag type. As such, a quantitative evaluation of the severity of voltage sag events can be achieved. Firstly, the user’s voltage tolerance curve is used to construct the comparison reference value of the energy index, in order to realize the rapid analysis of the severity of the sag event in the normal area and the abnormal area. Secondly, aiming at the problem of insufficient descriptions of the severity difference of sag events in uncertain areas, an improved energy index evaluation model combined with user tolerance characteristics is established through an interval division and interval weight calculation, so as to divide and evaluate the severity of sag events in uncertain areas. Considering the influence of the sag type on the voltage tolerance curve and user equipment, the energy index correction factor is then constructed, and the measurement function is used for an interval evaluation to obtain the ranking result of the voltage sag severity, which is more in line with the actual situation. Finally, the rationality and effectiveness of the proposed method are verified by analyzing 24 voltage sag events at a monitoring node.

The Safety Assessment of Unpowered Mooring Vessel Based on Unascertained Measure

2013 ◽  
Vol 361-363 ◽  
pp. 2156-2162
Author(s):  
Gui Bing Zhu ◽  
Xiao Fei Wen ◽  
Hu Liu
Keyword(s):  
Monte Carlo ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Simulation Method ◽  
Uncertain Information ◽  
Key Factors ◽  
Average Value ◽  
Final Weight ◽  
Interval Weight ◽  
Measure Evaluation

The safety of the unpowered mooring vessel was influenced by human factors, vessel condition, meteorological factors, hydrological and environmental factors. To ensure the safety of the unpowered mooring vessel during mooring, on the basis of unascertained measure evaluation model, the method of Monte Carlo and interval weight was put forward to assess the safety of the vessel. This method enables policymakers, in the treatment of evaluation, to avoid weighing the key factors from the traditional model. It also provides more valid intervals for policymakers while dealing with uncertain information of safety elements and errors caused by human preference. Through a random value of interval weight using Monte Carlo simulation method, the final average value of the simulation is taken as the final weight. Finally, a 16000t unpowered mooring cargo vessel is taken as an example to have a detailed discussion of the application of this method, and a safety result is obtained according to each key element. This method can provide new evaluation method and references to policymakers concerned.

A New Evaluation Model of Response Ability to Railway Dispatching Emergency

2012 ◽  
Vol 253-255 ◽  
pp. 1222-1226
Author(s):  
Si Yuan Qu ◽  
Xing Fang Xu
Keyword(s):  
Number Theory ◽  
Emergency Response ◽  
Evaluation System ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Decisive Role ◽  
Mean Value ◽  
Interval Number ◽  
Interval Evaluation ◽  
Weight Method

The emergency response ability plays a decisive role in the railway dispatching emergency disposal process and the evaluation of response ability is particularly important. Based on the establishment of evaluation system, the evaluation of response ability to dispatching emergency by interval number theory of uncertainty in mathematics was studied. With using [0,1] interval evaluation and taking three mean value to calculate index attribute and using weight method, the paper establishes the evaluation method of response ability to dispatching emergency. At last, taking the evaluation response ability to dispatching emergency of Shanghai Railway Bureau as example, it is proved that the proposed method is effective, simple and feasible. The new evaluation model would provide the reference for improving level of railway dispatching emergency disposal.

scholarly journals PPP Model Applicability Evaluation of Sewage Treatment Project Based on the Dual Perspective of Government and Private Sector

2021 ◽  
Vol 251 ◽  
pp. 01005
Author(s):  
Ren Xiaoqiang ◽  
Chen Ranran
Keyword(s):  
Private Sector ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Sewage Treatment ◽  
Reference Value ◽  
Comparison Method ◽  
Value For Money ◽  
Research Results ◽  
Dual Perspective ◽  
Applicability Evaluation

At present, the applicability evaluation perspective of PPP mode of sewage treatment project in China is single, and the operability of evaluation method is poor. On the basis of the existing evaluation methods, combined with the characteristics of China’s sewage treatment projects, this paper establishes the applicability evaluation model of PPP mode of sewage treatment projects from the dual perspectives of government and private sectors, and introduces the psc-ppp value comparison method and the marketability theory to evaluate the value for money. The research results show that the method is feasible and has practical reference value for the applicability evaluation of PPP mode in sewage treatment projects.

Failure Rate Evaluation of Sensitive Equipment Caused by Voltage Sag

2013 ◽  
Vol 321-324 ◽  
pp. 1434-1438
Author(s):  
Ying Zheng ◽  
Kai Gui Xie
Keyword(s):  
Failure Rate ◽  
Evaluation Model ◽  
Credibility Measure ◽  
Voltage Sag ◽  
Equipment Failure ◽  
Polynomial Fit ◽  
Failure Event ◽  
Evaluation Measure ◽  
Rate Evaluation ◽  
Tolerance Curve

In order to accurately evaluate sensitive equipment failure rate caused by voltage sag, the concept of credibility measure is introduced to measure the uncertainty of equipment failure event. This evaluation measure can avoid the deficiencies containing in classical probability measure which needs a large number of testing samples. The uncertainty of failure event is presented by a fuzzy measure where the membership function of equipment voltage tolerance curve corresponding to the characteristic quantities in the uncertain area was determined by fuzzy statistical and a polynomial fit method. Then the credibility distribution function was determined. The proposed evaluation model of sensitive equipment failure rate caused by voltage sag is developed. Using the practical testing samples, the personal computer (PC) was evaluated by the proposed method. Comparing the proposed method with current methods, the results have shown that the proposed method is proper, correct and credible. This method may be more practicable in practical condition.

A fuzzy evaluation method of road vehicle automatic weighing instrument in dynamic force metrological performance

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1365-1372
Author(s):  
Xiaohui Mao ◽  
Liping Fei ◽  
Xianping Shang ◽  
Jie Chen ◽  
Zhihao Zhao
Keyword(s):  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Dynamic Performance ◽  
Dynamic Force ◽  
Fuzzy Evaluation ◽  
Road Vehicle ◽  
Evaluation Standard ◽  
The Road ◽  
Metrological Performance

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.

scholarly journals An Intelligent Evaluation Method to Analyze the Competitiveness of Airlines

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Zhao ◽  
Xumei Chen
Keyword(s):  
Neural Network ◽  
Prior Knowledge ◽  
Evaluation Method ◽  
Standard Sample ◽  
Reference Value ◽  
The Self ◽  
Index Data ◽  
Som Neural Network ◽  
Simulation Results ◽  
Self Organizing

An intelligent evaluation method is presented to analyze the competitiveness of airlines. From the perspective of safety, service, and normality, we establish the competitiveness indexes of traffic rights and the standard sample base. The self-organizing mapping (SOM) neural network is utilized to self-organize and self-learn the samples in the state of no supervision and prior knowledge. The training steps of high convergence speed and high clustering accuracy are determined based on the multistep setting. The typical airlines index data are utilized to verify the effect of the self-organizing mapping neural network on the airline competitiveness analysis. The simulation results show that the self-organizing mapping neural network can accurately and effectively classify and evaluate the competitiveness of airlines, and the results have important reference value for the allocation of traffic rights resources.

Quantitative evaluation method of power supply reliability considering voltage sag

2021 ◽  
Vol 675 (1) ◽  
pp. 012121
Author(s):  
Pei Du ◽  
Yan Lin ◽  
Weijun Zhang ◽  
Zhixuan Liu ◽  
Fang Lin ◽  
...  
Keyword(s):  
Quantitative Evaluation ◽  
Power Supply ◽  
Evaluation Method ◽  
Voltage Sag ◽  
Supply Reliability

scholarly journals A multi-objective evaluation method based on connection numbers theory of hazardous chemical accidents emergency medical rescue capability

2019 ◽  
Vol 27 (3) ◽  
pp. 125-133
Author(s):  
Yapeng Wang ◽  
Jinguo Zhang ◽  
Yundou Wang ◽  
Xiaowen Xiong ◽  
Xin Zhao
Keyword(s):  
Index System ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Objective Evaluation ◽  
Evaluation Index System ◽  
Evaluation Index ◽  
Chemical Accidents ◽  
Hazardous Chemical ◽  
Emergency Medical ◽  
Partial Connection

Background: An objective, comprehensive and scientific evaluation of emergency medical rescue capability (EMRC) is of great realistic significance in assisting the health administrative department to grasp the overall response capability of all emergency medical rescue teams, enabling each team to have a full understanding of its own strengths and weakness and improve itself accordingly. At present, the research on the evaluation of EMRC in Hazardous Chemicals Accidents (HCA) is not systematic and in-depth, and the existing research results also have some shortcomings, such as, the lack of strong theoretical support for the evaluation index system, the relatively single function of evaluation methods, and so on. Objectives: The objective of this article is to research the evaluation index system and a new evaluation method of EMRC in HCA to overcome the above shortcomings. Methods: It establishes an emergency medical rescue capability model by employing the competency model and then constructs the evaluation index system on the basis of the analysis of all the factors of emergency medical rescue capability in hazardous chemical accidents and sets up an evaluation model based on the theory of connection numbers and partial connection numbers. It determines the competence ranking of several emergency medical rescue teams and the competence state of an individual emergency medical rescue team by calculating the connection principal value, and it also predicts how the emergency medical rescue capability will develop based on the values of partial connection numbers. Results: The example shows that the calculation process of this model is relatively simple, and its assessment results are objective and authentic, and moreover, its multi-functions can make up for the deficiency of the simplified function of other evaluation models. Conclusion: This method is scientific and rational to some extent and can provide reference for evaluation problems of the same kind.

Voltage Sag Evaluation Method of a Real Distribution System Based on a Connection Number Model

2013 ◽  
Vol 341-342 ◽  
pp. 1363-1366
Author(s):  
Lang Bai ◽  
Le Yu
Keyword(s):  
Distribution System ◽  
Evaluation Method ◽  
Assessment Model ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Connection Number ◽  
Reliability Parameters ◽  
Real Distribution ◽  
System Components ◽  
Simulation Results

The evaluation results of power system are greatly influenced by the reliability parameters and uncertainty of system components. The connection number assessment model and an approach have been presented to assess the occurrence frequency due to voltage sags. The proposed method had been applied to a real distribution system. Compared with the interval number method, the simulation results have shown that this method is simple and flexible.

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